As a result of the advent of a long-life blue light-emitting diode with low power consumption in recent years, a light-emitting diode (LED) element has been mounted widely not only on various illumination devices but also on many electronic devices typified by mobile phones and various control devices. If used as a light source of such illumination devices, key illumination of electronic devices, and backlight, for example, a single LED element is not enough to provide a sufficient amount of light. Accordingly, a plurality of LED elements arranged in a light-emitting device have been employed.
Japanese Patent Application Laid-Open No. 2009-283653 discloses a light-emitting device known as an example of the aforementioned conventional device. As shown in FIG. 12, this light-emitting device includes a substrate 1 composed of a metal plate divided into a first portion 2 and a second portion 3 with a gap 8 provided therebetween, a plurality of LED elements 5 mounted on the second portion 3 of the substrate 1 and electrically connected to the first portion 2 through wires 4, a reflecting frame 6 surrounding the LED elements 5, and a light-transmitting member 7 sealing the LED elements 5.
The conventional light-emitting device with this structure allows heat generated due to the light emission of the LED elements 5 to be dissipated from the substrate 1 composed of the metal plate or the reflecting frame 6.